278 Proceedings of Royal Society of Edinburgh. [sess. 
weed was then drained, pressed between filter-paper, dried in the 
air, and then in a desiccator until it was quite brittle, when it was 
reduced to a fine powder in a mortar, and the powder then dried 
in a weighing bottle. All the different determinations were made 
on portions of the same stock of seaweed thus prepared. 
Ash . — To obtain the ash, weighed quantities of the weed were 
ignited in a platinum crucible until the residue was of constant 
weight. We give below all the results obtained, but may remark 
that (2) and (3) are probably too low, from loss of sodium or 
potassium chloride. 
(1) 0-6502 grm. yielded 
o-iooi 
grm. ash= 15*39% 
(2) 0-4582 „ „ 
0-0667 
„ „ =14-56,, 
(3) 0-4753 „ 
0-0698 
„ „ =14-68,, 
(4) 0-4958 „ 
0-0762 
i! >) = 15 '37 ,, 
(5) 0-3248 „ „ 
0-0499 
„ „ =15-36,, 
Mean 15-07% 
Total Nitrogen . — by Dumas’ method. 
(1) 0*5280 grm. gave 27*6 c.c. nitrogen at 16° C. and 764 mm. 
= 26-21 c.c. at N.T.P. =0-032836 grm. = 6-22%. 
(2) 0*1986 grm. gave 10’5 c.c. nitrogen at 19° C. and 764 mm. 
= 9-87 c.c. at N.T.P. = 0*01237 grm. = 6*23%. 
(3) 0*7122 grm. gave 36*6 c.c. nitrogen at 17° C. and 764 mm. 
= 34-63 c.c. at N.T.P. = 0*043382 grm. = 6*09%. 
Mean = 6*18 „ 
Carbon and Hydrogen . — The powdered weed was ignited in 
closed combustion tube with chromate of lead. 
(1) 0-6127 grm. gavel °‘ 2937 grm - H 2 0 -0*0326 grm. H- 5*33%. 
to-' 
C0 2 =0-2164 
(2) 0-6560 
•7936 
•3075 „ H 2 0 = 0-0342 
0-8413 „ C0 2 =0-2294 
Mean % of hydrogen = 5*27 
,, carbon =35*15 
” to-* 
C =35-32 
H= 5-21 
C = 34-98 
